Timing and release mechanism for mechanical time fuses



Mrch 7, 1939. -E. H. scmaNK 2,149,469

TIMING AND RELEASE MECHANISM FOR MECHANICAL TIME FUSES lFiled. Aug'. 27, 1935 L gill, 47

644g INVENTOR Patented Mar. 7, 1939 TIMING AND ananas RELEASE mncnmsu ron.

car. 'mm FUsEs lPA'rlazN'r oFFlcE Edouard Il.A Schenk, New York, N. Y., assigner, Edgar by direct and mesne assignments,

Brandt, Paris, France Application August z'z, 1935, serial No. asma ,4 Claims.

The present invention relates to mechanical time fuses having a hollow body formed by a fixed base and an adjustable setting cap, a rotary timing mber set in angular position be- 5 fore theiire by means of said setting cap, a motor to drive said timing member in opposite direction during the night oi' the projectile, a clock-mechanism to govern the speed of said motor and a spring-pressed striker normally,

lo held in armed position and released after a predetermined time of ight by means of a release mechanism controlled by said timing member. In these fuses, the driving force controlling the action of the timing and release mechanism during the lght of the projectile is applied by either a spring motor, or a weight submitted to the centrifugal action due to the spin of the shell, or a vane which is withheld fromv spinning with the shell by air resistance. My invention is applicable to mechanical fusesuhaving any of these three types of motor above indicated, and it consists in a novel construction and arrangementl of the timing and release mechanism, which determines, with the help of J the clock mechanism of the fuse, the length of time which shall elapse between the iiring of the projectile and its bursting.

For convenience of illustration and explanation, I have shown, andwill hereinafter describe, my present invention vas applied to a mechanical time fuse having a spring motor, a clock mechanism actuated by said motor and an external setting cap, of essentially the type and character of that disclosed and illustrated 35 in my pending applications for Letters Patent of the United States Number 38,012 led August 27, 1935, and No. 41,990 filed September 25, 1935, although without intending thereby to indicate any limitation of the invention thereto.

secure in the patent to be issued upon the present application is concerned, I desire to state that this invention is applicable to any type of mechanical time fuse having an exterior setting cap and, an interior clock mechanismvand a rotary timing member coupled to said cap during the setting operation and actuated by said clock mechanism during the. night of the projectile, and is limited to the novel and peculiar timing and release mechanism hereinafter vset forth.

I will now proceed to a detailed description of the invention in connection with the drawing, in which:

Figure 1 is a partial side elevation and a par- 55 tial axial section of a mechanical time fuse.

So far as the protection which I desire tov provided with an embodimentof` this novel tlming and release mechanism, and Figures 2 and 3 vbase the amount of friction being made adjustable by means oi three set screws 40, pressing against a friction ring 4l, made of the best fitting material.. This setting cap is likewise l5 provided with tjhe usual setting slot 5 and with the index 6, marked on its lower edge, opposite the scale 3. i shows the usual nose cap screwed into the cap .v

According to my invention the timing organ is constituted by the cylindrical casing 2l containing all the moving parts of the clock mechanlsm of the fuse. As said clock mechanism is not a part of the invention, it has not been Y shown on the drawing. 25

This cylindrical casing 2| is rotatably mounted in a corresponding bore of the setting cap 4 and is normally coupled to said cap by means of four balls 42,l lodged partly in four corresponding spherical sockets vprovided in the outside periphery of the'casing 2l and partly in four opposite sockets provided in the inside periphery of the setting cap 4. lFour radial escape holes'43 are cut through the wall of said cap under these sockets .to allow for the escape of the. balls 42 35 under the action of the centrifugal force when the casing 2l sets back by inertia as will be now more fully described. v

The cylindrical casing 2l pivots in the axisof .the fuse inside the cap 4 between two ball Abear- 40 ings: an upper one (not shown) and a. lower one 44, the lower race 45 of which leans upon a percussion spring 46 so as to act as a shock absorber. Upon the ring of the projectile, the

. casing 2l sets slightly back by inertia until this 45 lower bearing '45 meets the upper edge of a cylindrical guide 48 carrying a tiring pin 41.

The coupling balls 42 are thus brmight opposite the radial holes 43 and are then free to escape under the action of thecentrliugalforce 50 developed by the spin of the projectile, thus uncoupllng the casing 2| from the cap I at the end of the acceleration of the projectile.

49 indicates a cylindrical bore cut in the base I vaccording to the axis of said base, along which the firing pin @il is guided by means of its csrrier fifi. This latter is provided with a concave annular rim 5U, which cooperates with a locking ball 5|, lodged at the inner end of a radial escape hole 52, cut into the base I. The outer end of said hole is closed by a plug 53, screwed into the base l.'

The locking ball 5| is normally held in its operative position by the periphery of a release shaft 54, provided with a spherical notch 55 and submitted to the action of a spring 56, bearing upon a plug 51, screwed into the base I. This release shaft 54 is provided with an upper dat projection 58, which cooperates with a release notch 59, cut into an annular rim or projecting edge 68, provided at the lower end of the casing 2l.

This rim constitutes at the same time the timing ring of the fuse and the rotary organ controlling the release of the tiring pin l.

In, the position shown on the drawing, which is the normal position of rest of the fuse, though the notch 5i? is aligned with the fiat head 53 of the release shaft 55, this release of the ring pin d'1 cannot occur because a tooth 62 of a lead washer 5| closes then the notch 59.

The lead Washer 5| is normally frictionally held into the rim te, but when the casing 2| sets back by inertia upon the ring of the projectile, this washer is empaled upon four steel points 53, xed in the base i and is thus uncoupled from the casing 2| and coupled to the base when, at the end.

' The spring 56 holds the release shaft fiat head 58 pressed under the tooth G2 of the lead washer 6|.

When the fuseis set, the setting cap d, the casing 2|', coupled to this cap by the coupling balls 2 and the lead washer 60, coupled to the casing 2| by the tooth G2, are solidarily rotated to the desired angular position, in accordance with the fuse range data, by the fuse setter pawls engaging the slots 2 and 5, respectively of the base and of the cap 4.

The release shaft 54 is then held in its operative position, shown in the drawing, by the annular rim 60, the bottom of which is flush with the lower face of the tooth 52, instead of being held by this latter.

Upon the ilringof the projectile, the casing 2| and the release shaft 54 set back by inertia against the action of, respectively, the springs 46 and 5G, until the race i5, acting as a shock absorber, meets the top of the firing pin carrier 48, while the lead washer 6| is empaled on the steel points 63 and the coupling balls 42 escape in the holes 43 under the action of the centrifugal force developed by the spin of the projectile. As long as the acceleration of this latter lasts, the casing 2| remains momentarily coupled to the base through the intermediary of the lead washer 6|, which prevents any unsetting by angular inertia Vof said casing.

essence while the lead washer Si remains hooked or empaied on the points 63. The casing 2| is vthen iree to start its back motion under the action of the clock mechanism until the release notch 59 comes opposite the dat head 58 of the release shaft 54. As the tooth 62 does nc more interfere with the release mechanism, this shaft 54 is now free to be pushed by its spring 58, its flat head 58 entering into the release notch 59. The locking ball 5|, under centrifugal action and considerable side pressure from. the ring pin M, 6B, enters then into the spherical notch 52, thus releasing the firing pin 41 at the instant the release shaft head 58 enters into the release notch 5B.

Driven by the percussion spring d6, the firing pin el? then strikes the primer 84, and successively detonates the tetryl pellets in the booster and finally the bursting charge in the projectile.

The main advantages oi this timing and release mechanism are that the fuse may be set in either direction for a range of settings varying between l and 10o seconds, as there are no abutment limiting the angular displacement of the setting cap d and that the friction of the release shaft dat head 5% under the rim GB is reduced to a minimum due to the fact that the spring 55 is much weaker than the percussion spring de.

What I claim and desire to secure by Lch ters Patent is:

l. In a timing and release mechanism for strtillery projectile fuses having a setting cap .with an axial bore and a base having a radial as `:veil as a longitudinal bore; a firing pin slidably and axially mounted in the 'oase of the fuse, a spring acting on said ring pin, a locking ball slidably mounted in the radial here of said base and nor- :nelly restraining said dring pin against the ac- V tion of said spring. a release shaft slidably mounted in the longitudinal bore of said base and noring on said release shaft and tending to force it to a position release said hall, a cylindrical clockwork casing rotatably and slidahiy mounted in the axial bore of said setting cap, a timing rim formed in the bottom of this casing, a release notch provided in this timing rim, safety means carried inside this timing rim by said casing and normally holding this release shaft in the position whereby it holds said ball immovable, reieasable meansto couple positively this casing to said setting cap before the ring of the projectile and means frictionally mounted in said timing rim and actuated by the setback of this casing due to ring of the projectile to hold this casing momentarily coupled to said base during the acceleration of the projectile, said casing, following said momentary coupling, being actuated to position said release notch in line with said release shaft, whereby said .release shaft is moved to release said locking bail and said firing pin.

2. A timing and release mechanism according to claim 1 in which the last mentioned coupling means comprises a. washer normally held by mere friction into the timing rim of the clockwork casing of the fuse while the'safety means consists of a. tooth, formed at the periphery of this washer, which. closes the release notch of this timing rim until the end of the acceleration of the projectile.

3. A timing and release mechanism according to claim 1, in which the last mentioned coupling means comprises a. washer of soft metal normally held by mere friction intothe timing rim of the clockwork casing of the fuse and a circular series Aof steel points fixed to the base of the fuse under this washer.

4. A timing and release mechanism according to claim 1 in which the rst mentioned releasable coupling means comprises at least a spherical socket provided in the outer periphery of the clockwork casing, a corresponding half-socket provided in the inner periphery of the setting cap. a radial bore provided through the setting cap slightly under said sockets, at least a coupling ball normally held into these two sockets by the action of the ring pin spring and actuated by the setback of the clockwork casing against'the action of said spring so as to escape under cen- EDOUARD H. SCHENK. 

